Major Lipids and Future Risk of Pneumonia: 20 year Observation of the Atherosclerosis Risk in Communities (ARIC) Study Cohort

Background: Circulating lipids have been implicated as important modulators of immune response and altered lipid levels correlate with the severity of infection. However, long-term prognostic implications of lipid levels regarding future infection risk remain unclear. The current project aims to explore whether baseline lipid levels are associated with risk of future serious infection, measured by hospitalization for pneumonia.

Methods: A retrospective analysis was performed in 13,478 participants selected from the Atherosclerosis Risk in Communities (ARIC) study, a large community-based longitudinal cohort in the United States with a median follow up time of >20 years. First incident of hospitalization for pneumonia was identified through hospital discharge records. Cox proportional hazard models were used to assess the association of baseline major lipid levels (total cholesterol, LDL-C, HDL-C, triglycerides) with time to first pneumonia hospitalization.

Results: A total of 1969 (14.61%) participants had a pneumonia hospitalization during a median follow up time of 21.5 years. The hazard ratio (HR) for pneumonia hospitalization was 0.90 (95% CI 0.87-0.92) for every 10 mg/dl increase in baseline HDL-C, and 1.02 (95% CI 1.02-1.03) for every 10mg/dl increase in baseline triglycerides. HDL-C and triglycerides both remained significant predictors of pneumonia hospitalization after multivariable adjustment. Such associations were not seen with baseline LDL-C or total cholesterol levels.

Conclusion: Lower baseline HDL-C and higher triglyceride levels were strongly associated with increased risk of long term pneumonia hospitalization in a large longitudinal US cohort.

Keywords: ARIC cohort; Lipids; Observational cohort; Pneumonia.